Evaluación y análisis de sus propiedades de su durabilidad y de la aplicación de los morteros reciclados que utilizan materiales secundarios

Tesi per compendi de publicacions.Versió amb una secció retallada, per drets de l'editorIn recent years the increase in waste generated by various sectors has caused problems of waste management that mostly have as final destination the landfills; however, this option it is unacceptable for the economic and environmental problems that these entail. On the other hand, the construction sector plays an important role in the economic development of a country; nevertheless, it generates a great environmental impact due to the extraction of virgin materials. Since the natural resources in the construction are limited, is appropriate and necessary the search for alternatives that comply with comparable functions to the usual aggregates, and also reduce the consumption of non-renewable resources. Therefore, recycled materials proceeding from residues of construction and demolition or other solid residues, can be harnessed by using them (through a suitable process) as recycled aggregates in concrete and mortars. Since the current regulations do not allow the use of aggregates in their fine fraction in concrete, and their use in mortars has not yet been regulated; This study addresses the study of mortars that incorporate recycled fine aggregates from concrete, glass and ceramic materials to replace different percentages of the usual aggregate (10, 15, 20, 30, 50, 60 and 100%). The research focuses on the particular scientific study of the aspects and characteristics of each recycled mortar and of the own waste that is used; which, prior to the manufacture of mortars was them required his characterization (as also of the aggregate usual one) for its comparison and comparable adequacy for its use in mortars. Manufacture of mortars; tests were carried out corresponding to its fresh state (consistency, density and air content) and hardened (density, absorption, compression, flexure and modulus of elasticity), as well as durability (basic, total and drying shrinkage) at different ages of study. As regards the properties in fresh condition, the research presented as additional variable the effect of the cement:sand ratio (1:3.25, 1:4 and 1:4.75). Since this thesis satisfies the publication compendium modality, three articles are presented, of which two refer to the properties of the mortars, and one to recycled concrete. The first article undertakes the study of the properties in fresh state of mortars with different percentages of ceramic aggregate and for the different cement:sand ratio; with the experimental results obtained, an interaction diagram was obtained which easily relates the properties of the same with reference to the percentage of substitution. The second article presents the results obtained in the study of the properties in hardened state (with emphasis on the modulus of elasticity) of the mortars, in which by means of specific analysis of the stress-strain curve characteristic of the same, obtained the properties of tenacity and resilience; As well as the numerical extrapolation of its equations that allow its prediction. The third publication presents the study of concrete manufactured with coarse recycled aggregate from wastes of concrete as a substitute for the usual aggregate; in these, different percentages of an additive with origin in PET were also used. This additive was obtained through a chemical process and incorporated as improvement of microstructure of concrete, which translates into a decrease of high porosity caused by the use of the recycled aggregates. As an annex to this thesis, other articles complementing the study carried out with the research theme are provided, which deal with different mortar properties with recycled aggregates of glass and concrete.En los últimos años el aumento de residuos generados por diversos sectores ha ocasionado problemas de gestión de residuos que en su mayoría tienen como destino final los vertederos; sin embargo, esta opción es inaceptable por los problemas económicos y medioambientales que estos conllevan. Por otra parte, el sector de la construcción desempeña un importante rol en el desarrollo económico de un país; no obstante que éste genera un gran impacto ambiental debido a la extracción de materiales vírgenes. Debido a que los recursos naturales necesarios en la construcción son limitados, es adecuado y necesario la búsqueda de alternativas que cumplan con funciones equiparables a los áridos usuales, y así mismo reduzcan el consumo de los recursos no renovables. Por tanto, materiales reciclados procedentes de residuos de construcción y demolición u otros residuos sólidos, pueden ser aprovechados utilizándoseles (mediante un proceso adecuado) como árido reciclado en hormigones y morteros. Puesto que la normativa actual no permite el uso de áridos en su fracción fina en hormigones, y su uso en morteros aún no se ha normado; en esta investigación se aborda el estudio de morteros que incorporan áridos finos reciclados procedentes de hormigón, vidrio y materiales cerámicos en sustitución de diferentes porcentajes del árido usual (10, 15, 20, 30, 50, 60 y 100%). La investigación se centra en el estudio científico particular de los aspectos y características de cada mortero reciclado y del propio residuo que es utilizado; los cuales, antes de la fabricación de los morteros se les requirió de su caracterización (como también del árido usual) para su comparación y adecuación equiparable para su usarse en morteros. Fabricar los morteros, se efectuaron ensayos característicos de su estado en fresco (consistencia, densidad y contenido del aire) y endurecido (densidad, absorción, compresión, flexión y módulo de elasticidad), así¿ como de durabilidad (retracción básica, total y por secado) a diferentes edades de estudio. En cuanto a las propiedades en estado fresco, la investigación presentó como variable adicional el efecto de la relación cemento:arena (1:3.25, 1:4 y 1:4.75). Puesto que esta tesis satisface con la modalidad de compendio de publicaciones se presentan tres artículos, de los cuales dos hacen referencia a las propiedades de los morteros, y uno a hormigones reciclados. El primer artículo acomete el estudio de las propiedades en estado fresco de morteros con diferentes porcentajes de árido cerámico y para las diferentes relación cemento:arena; con los resultados experimentales obtenidos se obtuvo un diagrama de interacción que relaciona de una forma fácil, las propiedades de los mismos con referente al porcentaje de sustitución. El segundo artículo presenta los resultados obtenidos en el estudio de las propiedades en estado endurecido (con énfasis en el módulo de elasticidad) de los morteros, en el que por medio de análisis especifico de la curva tensión-deformación característica de los mismos se obtienen las propiedades de su tenacidad y su resiliencia; así¿ como la extrapolación numérica de sus ecuaciones que permiten su predicción. La tercera publicación presenta el estudio de hormigones fabricados con árido grueso reciclado proveniente de residuos de hormigón como sustituto del árido usual; en estos, se utilizaron además diferentes porcentajes de un aditivo con origen en PET. Dicho aditivo fue obtenido por medio de un proceso químico e incorporado como mejora de la microestructura de los hormigones, la cual se traduce en una disminución de la alta porosidad ocasionada del uso de los áridos reciclados. Como anexo de esta tesis, se proporcionan otros artículos que complementan parte del estudio realizado con el tema de investigación, los cuales versan de diversas propiedades de morteros con áridos reciclados de vidrio y de hormigón.Postprint (published version

Total replacement of recycled aggregate and treated wastewater: concrete recycling in extremis

Million tons of construction and demolition waste (CDW) are generated every year around the world, and most of them are not adequately disposed, generating significant pollution on water, soil and air. Additionally, the use of freshwater in industrial processes, such as the production of cement, concrete manufacturing and curing for newly-built structures; has damaged the health of our freshwater ecosystems, reducing their volume and hindering their natural cycle of renovation. Therefore, the incorporation of recycled aggregate (RA) and treated wastewater (TW) as substitutes for the usual aggregates (UA) and freshwater, could generate significant environmental benefits. In this research, a comparative analysis of the experimental results of the properties of fresh and hardened concrete with different replacement percentage of UA for RA, is presented; and as an innovation the use TW. The results show that, regardless of the replacement percentage and use of treated wastewater, a concrete with RA and TW (recycled concrete in extremis, CRiE) had a satisfactory and acceptable or equivalent performance, not differing significantly from the performance of conventional concrete (CC), confirming that the use of RA for concrete building is feasible.Peer ReviewedPostprint (published version

Characterization of three recycled materials for alternative use of mortars

Because natural resources in construction are limited, it is advisable to look for new alternatives that meet comparable functions, and likewise, reduce consumption of non-renewable resources. The use of recycled materials is of benefit to the uncontrolled eliminations of residues that cause the use of the public resources, such as landfills. In addition, this contributes to the reduction of the environmental imact caused by the industries in the process of obtaining the same ones. Therefore, recycled materials such as concrete or masonry demolished, glass and ceramics different, can be employed in different ways to be used in the construction industry. This work focuses on presenting the initial characterization of three reveled materials as an alternative to use in relacement of natuals sand in mortars, this as a first step for furher study in different percentages of replacement, as currently his inderstanding is unknown, or little known.Peer ReviewedPostprint (published version

Metamorphosis in the porosity of recycled concretes through the use of a recycled polyethylene terephthalate (PET) additive. Correlations between the porous network and concrete properties

In the field of construction, sustainable building materials are currently undergoing a process of technological development. This study aims to contribute to understanding the behavior of the fundamental properties of concretes prepared with recycled coarse aggregates that incorporate a polyethylene terephthalate (PET)-based additive in their matrix (produced by synthesis and glycolysis of recycled PET bottles) in an attempt to reduce their high porosity. Techniques to measure the gas adsorption, water porosity, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to evaluate the effect of the additive on the physical, mechanical and microstructural properties of these concretes. Porosity reductions of up to 30.60% are achieved with the addition of 1%, 3%, 4%, 5%, 7% and 9% of the additive, defining a new state in the behavioral model of the additive (the overdosage point) in the concrete matrix; in addition, the porous network of these concretes and their correlation with other physical and mechanical properties are also explained.Peer ReviewedPostprint (published version

Implementation of Interaction Diagram of the Properties in Fresh for Mortars with Ceramic Aggregates

As the natural resources needed for the construction sector arelimited, new practices are being adopted for the managementof waste generated nowadays, including the use of constructionand demolition waste as aggregates for concrete and mortar.Considering the different typologies in construction wastes,ceramics are the second most representative material; thereforeit is important to validate their feasibility as a total orpartial replacement of natural aggregates. This work presentsa study of the properties in fresh state (consistency, density andair content) of mortars containing aggregates obtained fromrecycled ceramics, and their influence on the subsequent propertiesin the hardened state. A statistical analysis of experimentaldata was carried out by establishing regression coefficients,and then a triple-entry graph was obtained, allowing the differentproperties of mortars to be easily linked and simplifyingthe prediction of the relationships they will present since themixture design phase.

Simulation and comparative analysis of waste in concrete slabs

Construction sector generates significant amounts of waste that affects the environment and obstructs a sustainable development. The horizontal structure (slabs and roofs) is one of the building elements, by its functional requirement (geometry and layout) and volume, who uses more raw material for its constitution (potential generators of waste) On the other hand, the choice of the system to use, is typically based on criteria such as the ease of construction, the economy availability or the technological feasibility; so, from a sustainable perspective, the generation of waste has not been considered or evaluated. This work compares and analyzes four different common elements used in slabs and the possible generation of waste produced for the construction and eventual demolition of them, in order to provide a new weighting criterion in the choice.Peer ReviewedPostprint (published version

Simulation and comparative analysis of waste in concrete slabs

Construction sector generates significant amounts of waste that affects the environment and obsturcts a sustainable development. The horizontal structure (slabs and roofs) is one of the building elements, by its functional requirement (geometry and layout) and volume, who uses more raw material for its constitution (potential generators of waste) On the other hand, the choice of the system to use, is typically based on criteria such as the ease of construction, the economy availability or the tecnological feasibility; so, from a sustainable perspective, the generation of waste has not been considered or evaluated. This work compares and analyzes four different common elements used in slabs and the possible generation of waste produced for the construction and eventual demolition of them, in order to provide a new weighiting criterion in the choice.Peer ReviewedPostprint (published version

Characterization of three recycled materials for alternative use of mortars

Because natural resources in construction are limited, it is advisable to look for new alternatives that meet comparable functions, and likewise, reduce consumption of non-renewable resources. The use of recycled materials is of benefit to the uncontrolled elimination of residues that cause the use of the public resources, such as landfills. In addition, this contributes to the reduction of the environmental impact caused by the industries in the process of obtaining the same ones. Therefore, recycled materials such as concrete or masonry demolished, glass and ceramics different, can be employed in different ways to be used in the construction industry. This work focuses on presenting the initial characterization of three recycled materials as an alternative to use in replacement of natural sand in mortars, this as a first step for further study in different percentages of replacement, as currently his understanding is unknown, or little known.Peer ReviewedPostprint (published version

Propiedades en estado fresco de morteros con árido reciclado de hormigón y efecto de la relación c/a

Los residuos de construcción y demolición se han convertido en un problema urbano que resulta complejo y de un alto coste de gestión. Por este motivo, en la actualidad se está innovando en legislación medioambiental para fomentar diferentes actividades que lo mitiguen; siendo el reciclado una de las más aptas (faculta su reinserción como material de segunda generación para su nuevo uso en la construcción). En esta dirección se han realizado varios estudios de morteros en los que los residuos sustituyen diferentes porcentajes de los áridos naturales, a falta de una legislación propia que marque pautas de combinación. Sin embargo, poco se ha indagado en el comportamiento de su estado en fresco, el cual es vinculado con sus propiedades en estado endurecido a posteriori. En esta investigación se han realizado ensayos de propiedades en estado fresco (consistencia, densidad y contenido de aire) de morteros que contienen diferentes porcentajes de sustitución de áridos naturales, remplazados por áridos de hormigón reciclado (10, 20, 30, 50 y 100 %) a diferentes relaciones de cemento/arena (1:3.25, 1:4 y 1:4.74). Los resultados obtenidos muestran que los morteros con áridos reciclados reportan menor densidad, necesitan mayor cantidad de agua para lograr la consistencia requerida y presentan mayor contenido de aire que los morteros de referencia, sin sustitución de áridos reciclados.Peer ReviewedPostprint (published version

Synthesis and characterization of PET polymer resin for your application in concrete

Due to the problem that represents the accelerated production of waste from the consumption of polyethylene terephthalate (PET), it becomes necessary to look for alternative solutions; chemical recycling is a suitable method for conversion into a material with potential application in concrete additive, such as are unsaturated polyester resins; with the above improvements, and conservation of non-renewable raw materials can reduce the environmental impact. This investigation was focused on obtaining the synthesis of a polymeric resin by the method of glycolysis, and their characterization by Infrared Spectroscopy (FT-IR); the results show that the recycled materials (PET and its processing) are similar to reagents made from primary materials so that it is considered feasible to use in the intended application.Peer ReviewedPostprint (published version